The present invention relates to a tool holder with a protective hood with a conical part and a draw-in member connected thereto, wherein the protective hood has a cover piece, which is adapted to the conical part and envelops this conical part so as to be soil-proof, and a flexible clamping device, which locks detachably the draw-in member, wherein the draw-in member has a notch, and the flexible clamping device has a stop tab, which engages with the notch by means of a projection formed on the flexible end.
Such tool holders serve as chucks for different cutting tools such as drill, milling machine, grinding attachments, etc. The tool holder itself is clamped into a machine tool and driven by this machine tool. Such a tool holder has generally a conical part, which is received by a corresponding cone-shaped fitting shape of the machine tool. To clamp into the machine tool, the tool holder is provided with a notch in the bottom part and a draw-in cone, which is fastened above the conical apex and which also has a notch.
Handling the tool holder requires that the sensitive tapered face be handled with care. If this tapered face becomes dirty, for example, due to the coolant of the cutting tool or the fine metal chips generated during cutting and the tool holder is inserted in this state into the machine tool, deposits and indentations form along the tapered face of the tool holder and machine tool. The penetration of the coolant can also cause corrosion.
The result is that the seat of the tool holder is no longer precisely defined but rather receives a slight play so that the cutting tools can no longer be accurately guided.
It is known to insert the tool holder, turned by 180.degree. when changing, into a receiving box. Such a storage results in the coolant located at the tool running downwards on the tapered face and soiling it. On the other hand, manual manipulation of the tool holder in the reverse position is dangerous because a user can readily slip when grasping the holder and be injured on a sharp cutting tool.
In the U.S. Pat. No. 4,196,506 an automatic tool changer is described in which the tool holder having a conical part and a draw-in member is received in the protective hood during its storage and transport. At the same time at the upper part a horizontally pivotable pawl is provided with a stop, whose shoulder can be made to engage with a flange of the tool holder, the pawl being under spring prestress.
In a tool store according to U.S. Pat. No. 4,182,021 a tool holder is held detachably in a protective hood; to this end, two clamps that are under spring pressure and provided at the protective hood grasp a tapered shaft segment of the tool holder.